RESUMO
Recent studies indicate that the antral follicle population may be of paramount importance to improve reproductive performance in cows. There is already an agreement that the antral follicle count (AFC; follicles ≥3 mm in diameter) is a highly variable trait among animals, but with high repeatability in the same individual. Thus, females can be classified into low, intermediate or high AFC. Several studies in Bos taurus show a positive correlation between AFC and fertility parameters, such as increased quantity and quality of embryos, better pregnancy rates, higher progesterone levels, among others. However, there is still no consensus on AFC in Bos indicus females and indicus-taurus. This article aims to discuss the main aspects related to the population of antral follicles and its relation to the reproductive performance associated with the most common techniques in assisted reproduction (timed artificial insemination, in vitro embryo production, embryo transfer and superovulation).
Assuntos
Feminino , Animais , Bovinos , Bovinos/anatomia & histologia , Bovinos/fisiologia , Fertilidade , Folículo Ovariano , Prenhez , Transferência EmbrionáriaRESUMO
Recent studies indicate that the antral follicle population may be of paramount importance to improve reproductive performance in cows. There is already an agreement that the antral follicle count (AFC; follicles ≥3 mm in diameter) is a highly variable trait among animals, but with high repeatability in the same individual. Thus, females can be classified into low, intermediate or high AFC. Several studies in Bos taurus show a positive correlation between AFC and fertility parameters, such as increased quantity and quality of embryos, better pregnancy rates, higher progesterone levels, among others. However, there is still no consensus on AFC in Bos indicus females and indicus-taurus. This article aims to discuss the main aspects related to the population of antral follicles and its relation to the reproductive performance associated with the most common techniques in assisted reproduction (timed artificial insemination, in vitro embryo production, embryo transfer and superovulation).(AU)
Assuntos
Animais , Feminino , Bovinos , Bovinos/anatomia & histologia , Bovinos/fisiologia , Folículo Ovariano , Fertilidade , Prenhez , Transferência EmbrionáriaRESUMO
This paper presents new concepts in the study of folliculogenesis and describes some of the current applications to reproductive biotechnology. The importance of better understanding this issue is addressed both for basic and applied research. After a brief review of the basic conceptions of the origin, formation, and growth of follicules according to stablished concepts, some controversial points, as the postnatal production of the follicles and the role of multioocyte follicles, are discussed. The importance of the ovarian follicular reserve is considered for fertility and reproductive parameters, as well as some questiones about the presence of multioocyte follicles in adult ovaries. Finally, some future prospects are proposed.(AU)
Assuntos
Folículo Ovariano/anatomia & histologia , Fertilidade/fisiologia , Oócitos/citologia , Biotecnologia/tendênciasRESUMO
This paper presents new concepts in the study of folliculogenesis and describes some of the current applications to reproductive biotechnology. The importance of better understanding this issue is addressed both for basic and applied research. After a brief review of the basic conceptions of the origin, formation, and growth of follicules according to stablished concepts, some controversial points, as the postnatal production of the follicles and the role of multioocyte follicles, are discussed. The importance of the ovarian follicular reserve is considered for fertility and reproductive parameters, as well as some questiones about the presence of multioocyte follicles in adult ovaries. Finally, some future prospects are proposed.